1. Field of Invention
The present invention relates to a substrate-check equipment, and more particularly to a substrate-check equipment that changes light intensity of a lamp to maintain captured image quality and quickly check a substrate.
2. Description of the Related Art
A substrate such as paper, glass, a fabric covered with a layer of resin or multiple layers of fibers formed on a substrate such as paper, glass, a fabric covered by impregnation methods is required to have excellent consistency of parameters for a high-value product.
Generally, a quality of the substrate can be determined by checking upper and lower surfaces of the substrate. A traditional method for checking the upper and the lower surfaces comprises turning over the substrate by operational personnel after checking one of the surfaces, but this wastes timetherefore robotic substrate-check equipment were used to turn over the substrate conveniently.
A conventional automatic substrate-check equipment comprises at least one conveyer, at least two image acquisition units, at least two lamps and a control unit. The conveyer is pervious to light. The lamp corresponds respectively to the image acquisition units. The control unit connects electrically to and controls the conveyer, the image acquisition units and the lamp. The control unit allows the conveyer to convey a substrate and allows the lamps to respectively face and emit lights to the upper and lower surfaces of the substrate. The upper and lower surfaces respectively reflect the lights. The image acquisition units respectively capture reflected light from the upper and lower surfaces to generate signals that are received by the control unit. After analyzing the signals by the control unit, the quality of the substrate can be determined.
However, substrates can be made of various materials and have various thicknesses. Furthermore, a substrate is designed to have thin portions and thick portions. The image acquisition unit of the conventional substrate-check equipment is a camera with a linear charge coupled device (linear CCD). The lamp of the conventional substrate-check equipment has a light source with a constant intensity. Consequently, reflected light reflected by the thick parts of the substrate is dark, which may not be captured clearly by the camera with the CCD and would lead to an inaccurate reading of the quality of the substrate.
The inaccurate reading can be eliminated by adjusting an aperture of a camera lens. When shooting the thick parts of the substrate, the aperture has to be enlarged. When shooting thin parts of the substrate, the aperture has to be narrowed. However, the aperture is adjusted by operational personnel, and consumes much time, conditions of the control unit for analyzing signals are also required to be adjusted and calibrated. Therefore, adjustments make a quality check procedure complicated and inconvenient.
To overcome the shortcomings, the present invention provides a substrate-check equipment to mitigate or obviate the aforementioned.